1. Field of the Invention
The present invention relates to a method of generating random numbers, and more particularly relates to a method of generating uniform or pure random numbers which do not substantially have a periodicity.
2. Description of the Related Art
Disordered random numbers having equal frequency of occurrence as a whole has been widely utilized in numerical simulation for analyzing social phenomena and physical phenomena. Coding system with random numbers has been also proposed in order to protect personal information in electronic trading, electronic patient charts and remote electronic diagnoses.
In general, random numbers are produced by means of software of electronic computer, in which algorithms for producing numbers with certain distribution properties are utilized. However, in case of generating random number by computer algorithms, since the random numbers are produced in accordance with certain mathematical formulae, pure random numbers having neither periodicity nor regularity could not be generated. Therefore, when important personal date is encoded with the aid of such pseudo-random numbers, encoded data might be easily decoded and no protection could be attained.
In order to mitigate the above mentioned drawback, there has been also proposed to generate random numbers on the basis of electric noises produced from electric elements such as resistor and diode. However, noise produced by a resistor has a so-called 1/f characteristic. That is to say, noise components of lower frequency have higher amplitude and noise components of higher frequency have lower amplitude. Therefore, when random numbers are generated on the basis of bivalent signals which are obtained in accordance with amplitude of noise, there is a problem that the thus generated random numbers have a periodicity due to 1/f characteristic. In this manner, uniform or pure random numbers having no periodicity could not be generated. A diode also produces 1/f noise, and therefore random numbers generated from the diode noise might also have a periodicity.